Sealing unit for a wheel bearing

Abstract

A sealing unit for a wheel bearing, including a cover cap of sheet metal on a rotationally fixed bearing ring. An elastic seal on the cover cap. A baffle plate which protrudes in a radial direction, displaced on a bearing ring which can rotate with respect to the rotationally fixed bearing ring. The cover cap has a rotationally symmetrical hollow shoulder which extends axially in the direction of roller bodies of the bearing. The seal is fixed with respect to the shoulder of the cover cap and at the same time the seal bears with at least one sealing lip, at least once in a radially sealing fashion against a hollow cylindrical section which is fixed with respect to the rotatable bearing ring and protrudes axially from the baffle plate in the direction of the bearing roller bodies.

1. A sealing unit for a wheel bearing, the sealing unit comprising:
 a cover cap made of sheet metal and attachable on a rotationally fixed bearing ring, the cover cap having a rotationally symmetrical shoulder which extends in the direction of roller bodies of the bearing, and the shoulder defines a hollow space, 
 a baffle plate extending in a radial direction and disposed on a rotatable bearing ring which can rotate with respect to the rotationally fixed bearing ring, 
 a hollow cylindrical section which is fixed with respect to the rotatable bearing ring and the cylindrical section protrudes axially from the baffle plate in the direction of the roller bodies of the bearing, 
 an elastic annular seal on the cover cap, the elastic seal being fixed with respect to the shoulder, the seal having at least one sealing lip which bears at least once in a radially sealing fashion against the hollow cylindrical section, 
 the annular seal protruding in an axial direction from the shoulder and in an annular shape and the seal projecting free of the shoulder and in the direction of the roller bodies of the bearing, wherein the seal projects from the shoulder by at least one third of the axial length of the shoulder; the seal along with the shoulder projecting freely from the cover cap in the axial direction, the seal being radially thicker than the thickness of the sheet metal of the cover cap, and starting from the shoulder, the freely projecting seal can be freely elastically varied in a radial direction by the shoulder, and 
 the seal is continuous, as it extends further, and the seal includes at least one sealing lip which bears in a sealing fashion against a section of the baffle plate. 
 
   
   
     2. The sealing unit as claimed in  claim 1 , wherein the section of the baffle plate comprises the hollow cylindrical section thereof. 
   
   
     3. The sealing unit as claimed in  claim 1 , wherein the sealing lip bears at two locations in a sealing fashion against the baffle plate, including the sealing lip having a free end which bears against the baffle plate in a sealing fashion in an axial direction. 
   
   
     4. The sealing unit as claimed in  claim 1 , further comprising a spring which engages annularly around the sealing lip and prestresses the sealing lip in a radial direction against the section of the baffle plate. 
   
   
     5. The sealing unit as claimed in  claim 1 , further comprising a presealing lip arranged radially between the shoulder and the section of the baffle plate. 
   
   
     6. The sealing unit as claimed in  claim 1 , wherein the cover cap is fixed with respect to an outer ring of the wheel bearing, and the baffle plate is fixed with respect to an inner ring of the wheel bearing. 
   
   
     7. The sealing unit as claimed in  claim 6 , wherein the cover cap is non-rotatable along with the outer ring of the wheel bearing and the baffle plate is rotatable along with the inner ring of the bearing. 
   
   
     8. A sealing unit as claimed in  claim 1 , wherein
 the wheel bearing has at least one pulse transmitter arranged axially between the cover cap and the roller bodies of the wheel bearing, 
 a securing plate with a hollow cylindrical segment which holds the pulse transmitter on the rotatable bearing ring, 
 the cover cap is comprised of a non-ferromagnetic sheet metal and is shaped and located to cover the at least one pulse transmitter at least in the axial direction, 
 the shoulder is arranged at least partially concentrically between the pulse transmitter and the section of the baffle plate, and the seal is arranged at least partially concentrically with respect to the hollow cylindrical segment of the securing plate. 
 
   
   
     9. A sealing unit as claimed in  claim 1 , wherein
 the wheel bearing has at least one pulse transmitter arranged axially between the cover cap and the roller bodies of the wheel bearing, 
 the cover cap is comprised of a non-ferromagnetic sheet metal is shaped and located to cover the at least one pulse transmitter at least in the axial direction, 
 the section of the baffle plate includes a side that is continuous facing the roller bodies of the bearing, the baffle plate having at least one circular ring section; 
 a securing plate which secures the pulse transmitter; the securing plate and the at least one circular ring section of the baffle plate holding the sealing lip axially between them. 
 
   
   
     10. A sealing unit for a wheel bearing, wherein the wheel bearing has a rotatable inner bearing ring, a rotationally fixed outer bearing ring, and roller bodies between the rings, and at least one pulse transmitter; the sealing unit comprising
 a cover cap comprised of a non-ferromagnetic sheet metal, the cover cap having a bottom part, the bottom part extending radially to cover the at least one pulse transmitter at least in the axial direction, the pulse transmitter is arranged axially between the cover cap and the roller bodies of the bearing, 
 the cover cap is fixed with respect to the rotationally fixed outer bearing ring, 
 an elastic seal fixed with respect to the cover cap and 
 a radially protruding baffle plate fixed with respect to the inner bearing ring, the inner bearing ring is rotatable with respect to the outer bearing ring, 
 the cover cap surrounding and being axially on the outside of the pulse transmitter, the cover cap extending radially between a radially inward part of the cover cap and the outer bearing ring, and the cover cap being securely seated radially on the outside on the outer bearing ring and including a rotationally symmetrical hollow shoulder which extends axially in the direction of the roller bodies of the bearing. 
 
   
   
     11. The sealing unit as claimed in  claim 10 , wherein
 the baffle plate is fixed with respect to the outer bearing ring the baffle plate and has a hollow cylindrical section which protrudes axially from the baffle plate axial in the axial direction to the roller bodies; and 
 the seal is fixed with respect to the shoulder of the cover cap, the seal includes at least one sealing lip and the at least one lip bears at least once in a radially sealing manner against the hollow cylindrical section on the baffle plate. 
 
   
   
     12. The sealing unit as claimed in  claim 11 , wherein the baffle plate has a continuous section, on its side facing the roller bodies and the continuous section includes a securing plate which secures the pulse transmitter, the securing plate and the baffle plate holding the sealing lip axially between them. 
   
   
     13. The sealing unit as claimed in  claim 12 , wherein the baffle plate cylindrical section has an annular groove therein which opens toward a circular ring section that is bent in the radial direction from the cylindrical section of the baffle plate, and the circular ring section has an axial wall thickness which is reduced at least by the radial depth of the annular groove compared with the wall thickness of the cylindrical section of the baffle plate. 
   
   
     14. The sealing unit as claimed in  claim 11 , wherein the cover cap is arranged at least partially concentrically between the pulse transmitter and the radially inward section of the cover cap,
 a securing plate with a hollow cylindrical segment which secures the pulse transmitter; 
 the seal is arranged on the inner bearing ring, at least partially concentrically with respect to the hollow cylindrical segment of the securing plate which secures the pulse transmitter.